Second in importance to pulmonary complaints in solipeds; equal in
ruminants. Extent of digestive organs and character of food, in
carnivora, herbivora, and omnivora. Ruminant’s stomachs. Gastric
fermentation. Foreign bodies. Torpor. Unwholesome fodder.
In the horse these maladies are only second in importance to those of
the respiratory organs, while in ruminants they are equally frequent and
important. The varying susceptibility of the digestive organs to disease
in different families and the special proclivity of different parts of
these organs may be, in great part, explained by the great variation in
the food, by the relative extent of the gastro-intestinal surface, and
by the amount of work devolving on the respective viscera.
In =carnivora= the entire gastro-intestinal surface is little more than
half the area of the skin, for their rich animal food does not require a
prolonged retention and an elaborate series of intricate processes to
insure digestion and absorption. This system of organs is accordingly
less liable to disorder in carnivora than in herbivora and omnivora. Add
to this that the carnivorous stomach is very capacious relatively to the
intestine, that the digestion of the great bulk of the food (nitrogenous
elements) is nearly completed in this viscus, and that the contents of
this organ are easily and completely discharged by vomiting whenever
they prove irritating, and we have ample explanation of the comparative
immunity of these animals from digestive disorders.
The =herbivora= stand at the opposite extreme, the gastro-intestinal
surface being over double the area of the skin in the horse, and nearly
three times that extent in the ox. The hard, fibrous and comparatively
innutritious vegetable food of these animals necessitates its prolonged
retention in the alimentary canal in order to the completion of
digestion and the absorption of the nutritive constituents. Hence the
great liability of the herbivora to diseases of the digestive organs.
=Omnivora= occupy a place intermediate between these two classes, as
regards both the nature of the food and the extent of surface of the
alimentary canal, and they are in similar ratio little liable to
digestive disorders. They have besides in common with carnivora a great
facility in the rejection of irritant matters by vomiting, and in thus
protecting themselves against gastric and intestinal disorders.
A fair idea of the area of the intestinal surface may be given by
stating the length of the canal relatively to that of the body:—in the
dog : : 6 : 1, in the rabbit : : 10 : 1, in the ass and mule : : 11 : 1,
in the horse : : 12 : 1, in swine : : 14 : 1, in the ox :: 20 : 1, and
in the sheep : : 27 : 1. The calibre of the intestine varies however and
with it the capacity. Thus in the relatively shorter intestine of the
horse, the capacity is much greater in ratio with the size of the animal
than is the relatively much longer intestine of the pig. The ox’s
intestine though twice the length of that of the horse has little more
than half the capacity.
Among =herbivora= the monogastric (horse, ass, mule), and polygastric
(ruminants) animals manifest varying pathological susceptibility
according to the relative development of the different digestive viscera
and the habitual character of their food. The horse and other large
solipeds have small stomachs (16 qts.) and capacious intestines (196
qts.). Digestion is restricted in the stomach and largely carried on in
the spacious bowels. The small stomach requires to be frequently
replenished in moderate amount, but, if this is secured, its liability
to disease is slight while that of the intestines is very considerable.
In the ox the stomachs have a total capacity of 252 qts., while that of
the intestines averages 103 qts. In this animal the capacious and hard
working stomach is a frequent seat of disorder, while the comparatively
small intestines are to a large extent exempt. The small stomach of the
horse is easily overloaded and disordered or paralyzed by an unusually
full feed of grain when hungry, or one of some specially appetizing
fodder, and the case is serious, as relief can rarely be obtained by
vomiting. For the same reason fermentation of the gastric contents with
evolution of gas and tympany usually proves fatal to the horse since
relief by eructation is too often impossible. Cattle are fitted to live
in damp localities where the cloven foot prevents sinking and getting
bogged, and where they may draw in with the tongue a full mouthful of
coarse herbage which they swallow with little mastication or admixture
with saliva. This lodges in the first two stomachs, and if, from any
cause, rumination is impaired, or suspended, it finds itself in
conditions especially favorable to fermentation. The food too, as in the
case of frosted roots, wet clover or partially ripened grain, etc., is
often charged with ferments (bacteria) in a state of great vital
activity, and hence the frequent tympanies of the ox. The ruminant is no
less liable than the soliped to overload the stomach, and though the
return of food from the first two stomachs to the mouth is a normal
process, this is promptly arrested by the supervention of paresis in the
overloaded and overdistended organs. This overdistension further tensely
stretches and closes the lips of the œsophagean opening. The rapid
swallowing of the food, with only one or two strokes of the teeth for
each morsel, renders the large ruminant more liable to take in poisons,
pins, nails and other injurious bodies, especially when hunger and the
blunting of the sense of smell have been brought on by traveling on
dusty roads. Again the large ruminants, and especially cows are wont to
while away the tedious hours by chewing and unwittingly swallowing
pieces of leather, cloth, bones, iron, etc. Once more the third stomach
in which the food is compressed and triturated between the multiple
folds, is normally comparatively dry, and is liable under dry, fibrous,
heating or stimulating aliment, or in case of fever, to dry up in part
or in whole, and to derange the whole process of digestion.
All herbivora are liable to disease from unwholesome fodder and the
resulting affection may prove epizootic in connection with unfavorable
seasons, or more local, from faulty cultivation.
The symptoms vary so much in connection with the seat and nature of the
disease that it would be impolitic to attempt to generalize them.